Uninterruptible power supplies (UPSs) are commonly employed to supply reliable power to one or more electrical loads. An uninterruptible power supply stores energy, typically within a collection of batteries, and delivers the stored energy to the electrical loads during a period of time when power from the primary power source, typically the electric power grid, is not available. In an on-line uninterruptible power supply, the uninterruptible power supply converts AC input power from the primary source to DC power and DC circuitry within the uninterruptible power supply converts the DC power to an AC output connected to the electrical loads. The collection of batteries are used to store energy in the uninterruptible power supply.
Photovoltaic devices are used to generate electrical power from ambient light. Photovoltaic devices are commonly used to power consuming loads such as lighting, heating, or to operate communications equipment. Photovoltaic devices may also be directly connected to the grid via a grid-connected inverter.
Uninterruptible power supplies are sometimes characterized by their efficiency at converting from AC power to DC power and DC power to AC power. A higher efficiency implies less wasted energy, less heat generated by the process, and greater financial savings. Similarly, photovoltaic applications are also often characterized by their efficiency at converting light to useful electrical energy. Higher efficiency implies a better use of the capital dollars expended to install the photovoltaic system.
Uninterruptible power supplies are also sometimes characterized by the duration of their ability to deliver energy in a form and manner suitable for use by a load in the event of a power failure.
At least some aspects of the present disclosure are directed to methods and apparatus for uninterruptible power supplies which incorporate photovoltaic devices and solar power kits.